This application relates to a photoresist removal method, including: acquiring a target wafer, a photoresist being provided on a surface of the target wafer, a surface of a photoresist layer of the photoresist being plated with a metal overhead layer; immersing the target wafer in a first organic solvent at a first temperature in a water bath for a first duration; rinsing the target wafer with a new first organic solvent in response to an end of the first duration; performing, in the first organic solvent, ultrasonic cleaning on the rinsed target wafer for a second duration based on a target ultrasonic power; removing the residual first organic solvent on the surface of the target wafer in response to an end of the second duration; and drying the target wafer with the solvent removed by simultaneous centrifugal drying and gas purging to obtain the target wafer with the photoresist removed.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A photoresist removal method, comprising: acquiring a target wafer, a photoresist being provided on a surface of the target wafer, a surface of a photoresist layer of the photoresist being plated with a metal overhead layer, the metal overhead layer comprising an air bridge structure; immersing the target wafer in a first container of first organic solvent for a first predefined duration, wherein the first container is placed in a water bath that has a first predefined temperature, the first predefined temperature and the first predefined duration are determined according to the first organic solvent; rinsing the target wafer with the first organic solvent in response to an end of the first predefined duration; placing the target wafer in a second container containing the first organic solvent at a second predefined temperature lower than the first predefined temperature, the target wafer having a target inclination angle against an interior side wall of the second container; suspending the second container containing the first organic solvent at the second predefined temperature on an ultrasonic cleaning water surface, wherein only a bottom surface of the second container contacts the ultrasonic cleaning water surface; performing ultrasonic cleaning on the target wafer placed in the second container that is suspended in the ultrasonic cleaning water surface for a second predefined duration based on a target ultrasonic power, the second predefined duration shorter than the first predefined duration; removing residual first organic solvent on the surface of the target wafer in response to an end of the second predefined duration; and drying the target wafer to obtain the target wafer having the air bridge structure with the photoresist removed from top and bottom of the air bridge structure via simultaneous gas purging and centrifugal drying.
2. The method according to claim 1, wherein the target inclination angle is 45 degrees.
3. The method according to claim 1, wherein removing the residual first organic solvent on the surface of the target wafer in response to the end of the second predefined duration comprises: placing the target wafer in a second organic solvent in response to the end of the second predefined duration; and performing ultrasonic cleaning on the target wafer for a third duration based on the target ultrasonic power to remove the residual first organic solvent on the surface of the target wafer.
4. The method according to claim 1, wherein drying the target wafer to obtain the target wafer comprises: standing the target wafer on a paper surface to perform preliminary drying; and drying the target wafer via the simultaneous gas purging and centrifugal drying after the preliminary drying to obtain the target wafer having the air bridge structure with the photoresist removed from top and bottom of the air bridge structure.
5. The method according to claim 1, wherein the centrifugal drying is centrifugally rotating the target wafer at a target rotation speed for a fourth duration.
6. The method according to claim 5, wherein the target rotation speed is 3000 revolutions per minute (rpm).
7. The method according to claim 5, wherein the fourth duration is 35 seconds.
8. The method according to claim 1, wherein the first organic solvent is a Remover PG solvent, the first predefined temperature is 80° C., and the first predefined duration is 96 hours, the second predefined temperature is 22° C. and the second predefined duration is 5 minutes.
9. The method according to claim 1, wherein the first organic solvent is an N-methylpyrrolidone (NMP) solvent, the first predefined temperature is 85° C., and the first predefined duration is 4 hours, the second predefined temperature is 22° C. and the second predefined duration is 5 minutes.
10. The method according to claim 1, wherein the air bridge structure is a discrete air bridge.
11. The method according to claim 1, wherein the air bridge structure is an all-inclusive air bridge including a plurality of serially connected air bridges.
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January 14, 2022
January 28, 2025
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